# base/big-delimiter-size-drop

Drop the fixed delimiter size imposed by \big.

https://texform.dev/rules/base/big-delimiter-size-drop

## Metadata

| Field | Value |
| --- | --- |
| Key | base/big-delimiter-size-drop |
| Level | equiv |
| Fidelity | reading |
| Enabled by packages | base |
| Profiles | Equiv |

## Rewrite patterns

### ordinary-delimiter

From:

```latex
\big (
```

To:

```latex
(
```

### scripted-ordinary-delimiter

From:

```latex
\big (_{#1}
```

To:

```latex
(_{#1}
```

### literal-left-angle

From:

```latex
\big <
```

To:

```latex
\langle
```

### literal-right-angle

From:

```latex
\big >
```

To:

```latex
\rangle
```

### control-left-angle

From:

```latex
\big\lt
```

To:

```latex
\langle
```

### control-right-angle

From:

```latex
\big\gt
```

To:

```latex
\rangle
```

### null-delimiter

From:

```latex
\big .
```

To:

```latex

```

### scripted-null-delimiter

From:

```latex
\big ._{#1}
```

To:

```latex
{}_{#1}
```

## Examples

Examples show the rule in isolation, not a complete normalization profile.

### Ordinary delimiter

Before:

```latex
a\big(b
```

After this rule:

```latex
a(b
```

Packages: base.

The rendered result has pixel differences from the input.

### Scripted ordinary delimiter

Before:

```latex
a\big(_i b
```

After this rule:

```latex
a(_i b
```

Packages: base.

The rendered result has pixel differences from the input.

### Literal left angle

Before:

```latex
a\big<b
```

After this rule:

```latex
a\langle b
```

Packages: base.

The rendered result has pixel differences from the input.

### Literal right angle

Before:

```latex
a\big>b
```

After this rule:

```latex
a\rangle b
```

Packages: base.

The rendered result has pixel differences from the input.

### Control left angle

Before:

```latex
a\big\lt b
```

After this rule:

```latex
a\langle b
```

Packages: base.

The rendered result has pixel differences from the input.

### Control right angle

Before:

```latex
a\big\gt b
```

After this rule:

```latex
a\rangle b
```

Packages: base.

The rendered result has pixel differences from the input.

### Null delimiter

Before:

```latex
a\big.b
```

After this rule:

```latex
ab
```

Packages: base.

Rendering verified with the declared packages.

### Scripted null delimiter

Before:

```latex
a\big._i b
```

After this rule:

```latex
a{}_i b
```

Packages: base.

Rendering verified with the declared packages.

## Triggers

- [\\big](https://texform.dev/latex/commands/big)

## Eliminates

- [\\big](https://texform.dev/latex/commands/big)

## Upstream

- [base/big-class-variants-to-big](https://texform.dev/rules/base/big-class-variants-to-big): Collapse \bigl, \bigr, \bigm to \big.

## Same family

- [base/Big-class-variants-to-Big](https://texform.dev/rules/base/Big-class-variants-to-Big): Collapse \Bigl, \Bigr, \Bigm to \Big.
- [base/Bigg-class-variants-to-Bigg](https://texform.dev/rules/base/Bigg-class-variants-to-Bigg): Collapse \Biggl, \Biggr, \Biggm to \Bigg.
- [base/big-class-variants-to-big](https://texform.dev/rules/base/big-class-variants-to-big): Collapse \bigl, \bigr, \bigm to \big.
- [base/bigg-class-variants-to-bigg](https://texform.dev/rules/base/bigg-class-variants-to-bigg): Collapse \biggl, \biggr, \biggm to \bigg.
- [base/Big-delimiter-size-drop](https://texform.dev/rules/base/Big-delimiter-size-drop): Drop the fixed delimiter size imposed by \Big.
- [base/Bigg-delimiter-size-drop](https://texform.dev/rules/base/Bigg-delimiter-size-drop): Drop the fixed delimiter size imposed by \Bigg.
- [base/bigg-delimiter-size-drop](https://texform.dev/rules/base/bigg-delimiter-size-drop): Drop the fixed delimiter size imposed by \bigg.
- [physics/absolutevalue-to-abs](https://texform.dev/rules/physics/absolutevalue-to-abs): Collapse absolutevalue to the shorter abs helper before fence expansion.
- [physics/evaluated-to-eval](https://texform.dev/rules/physics/evaluated-to-eval): Collapse evaluated to the shorter eval helper before eval expansion.
- [physics/quantity-to-qty](https://texform.dev/rules/physics/quantity-to-qty): Collapse quantity to the shorter qty helper.
- [physics/Bqty-to-brace-fence](https://texform.dev/rules/physics/Bqty-to-brace-fence): Rewrite Bqty to explicit brace fences.
- [physics/abs-to-vert-fence](https://texform.dev/rules/physics/abs-to-vert-fence): Rewrite abs to explicit vertical bar fences.
- [physics/bqty-to-bracket-fence](https://texform.dev/rules/physics/bqty-to-bracket-fence): Rewrite bqty to explicit bracket fences.
- [physics/norm-to-double-vert-fence](https://texform.dev/rules/physics/norm-to-double-vert-fence): Rewrite norm to explicit double-vertical-bar fences.
- [physics/pqty-to-paren-fence](https://texform.dev/rules/physics/pqty-to-paren-fence): Rewrite pqty to explicit parenthesis fences.
- [physics/eval-expand](https://texform.dev/rules/physics/eval-expand): Expand eval notation to the explicit fence-and-bar form.

## Notes

The existing class-variant rules produce this canonical size-tier command, so their produces-to-consumes dependency supplies the ordering. Dropping a visibly salient size tier loses grouping emphasis and visual hierarchy, so the output first enters Equiv; preserving delimiter identity, reading order, and structural role still supports Reading fidelity. The rule emits a canonical bare spelling for the delimiter identity: literal or control-sequence <, >, \lt, and \gt delimiters denote angle brackets here and must become \langle or \rangle rather than bare relation notation. A null delimiter may disappear only when doing so preserves slot and script binding; otherwise retain a necessary empty group.

## Disable this rule

```python
TransformEngine(profile="corpus", disable_rules=["base/big-delimiter-size-drop"])
```

```javascript
new TransformEngine({ profile: 'corpus', disableRules: ['base/big-delimiter-size-drop'] })
```

[Open in Playground](https://play.texform.dev/?input=a%5Cbig%28b)